(1) Field of the Invention
The present invention relates to an improved filter apparatus for removing debris from a free flowing water system. In particular, the present invention relates to a filter apparatus which has a continuous belt comprised of chain links forming openings in the belt. The front side of the belt collects debris as the water system flows through the openings of the belt. The belt moves along a path formed by a rail extending between an upper and lower sprocket cylinder. As the belt moves over the upper sprocket cylinder at the top of the apparatus, the sprocket teeth on the upper sprocket cylinder extend into the openings of the belt and loosen the debris collected on the belt which then drops into a trough. The belt also has lifters which enable the belt to move the collected debris upward. The lifters dump the collected debris into the trough as the lifters rotate over the top of the rail.
(2) Prior Art
The prior art has shown various types of filters or debris collecting apparatus which use a continuous conveyor-like belt to move the debris upward out of the water. Illustrative are U.S. Pat. Nos. 3,856,678 to Hagihara and 5,059,313 to Etschel.
Hagihara describes a filter medium for filtration of solids from a liquid flowing through a channel. The filter medium is in the form of an endless belt which extends over first, second and third shafts which rotate to move the belt through and up out of the water. The belt is comprised of filter units each having a shank portion and a hook portion which collect the debris as the filter units are moved through the water. As the filter units move over the third shaft, the hook portions of the filter units are caused to swing outward thereby casting off the collected debris. The filter medium does not adequately collect the debris and the filter units are not completely cleaned when the filter moves over the third shaft and dumps the debris.
Etschel et al describes a separating apparatus for sewage clarification plants. The apparatus consists of a plurality of rake sieve which are connected together and extend around an upper and lower reversing means similar to a conveyor belt. The rake sieve are made of alternately interconnected plates and spacer elements. The reversing means have sprocket teeth which engage the driver studs which extend outward from the underside of the spacer elements. The plates have a substantially hook-shaped form with a front edge directed outwardly from the plane of the rake sieve. The plates collect the solids from the water and transport the solids upwardly on the front side of the apparatus. A clearing comb meshes with the rake sieve and the plates of each rake sieve section and cleans the solid particles pressed into the rake sieve. The apparatus does not completely clean the rake sieve and thus allows build up of debris and other growth on the rake sieve.
Also of interest are U.S. Pat. Nos. 1,897,904 to Hurxthal; 2,307,601 to Nichols; 3,485,342 to Fechter; 3,872,006 to Abel and 3,975,275 to Kato which show different types of apparatus for removing debris from a free flowing water system. There remains a need however for an apparatus which removes debris from a free flowing water system and which completely cleans the openings in the belt to remove all the debris and to prevent the build up of flow restricting deposits in the openings.